PT  - JOURNAL ARTICLE
AU  - Galvanetto, Nicola
AU  - Maity, Sourav
AU  - Ilieva, Nina
AU  - Laio, Alessandro
AU  - Torre, Vincent
TI  - Unfolding and identification of membrane proteins from native cell membranes
AID  - 10.1101/732933
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 732933
4099  - http://biorxiv.org/content/early/2019/08/13/732933.short
4100  - http://biorxiv.org/content/early/2019/08/13/732933.full
AB  - Is the mechanical unfolding of proteins just a technological feat applicable only to synthetic preparations or is it applicable to real biological samples? Here, we describe all the steps necessary to deal with native membranes, from the isolation of the membrane of single cells, to the characterization and identification of the embedded membrane proteins. To do so, we combined AFM-based single-molecule force spectroscopy (SMFS) with an automatic pattern classification and the cross-matching of proteomic databases (Uniprot, PDB) to identify the unfolded proteins. We applied this method to four cell types: hippocampal and dorsal root ganglia neurons, rod outer segments and disks, and we were able to classify the unfolding of 5-10% of their total content of membrane proteins. The ability to mechanically probe proteins in their native environment enables the direct mechanical phenotyping of the membrane proteins from different cell types.